Thermoelectric materials and devices can be utilized to obtain electrical energy from a thermal gradient. Such materials have a limited thermoelectric conversion efficiency which can be defined in terms of the formula ZT=S2γ/κ×T. The figure of merit (ZT) is related to the macroscopic transport parameters of the material that includes the Seebeck coefficient (S), the electrical conductivity (γ), and the thermal conductivity (κ).
In attempts to improve the thermoelectric conversion efficiency of a thermoelectric material, one can attempt to increase the Seebeck coefficient and/or the electrical conductivity while decreasing the thermal conductivity. However, increasing the ZT has proven difficult since the three parameters S, γ, and κ are interrelated. For example, doping of a specific material can increase the electrical conductivity but decrease the Seebeck coefficient and/or increase the thermal conductivity.
Nanostructured materials have been studied to produce thermoelectric materials that have improved or higher figures of merit. However, such nanostructured materials can be difficult and expensive to manufacture, difficult to process to form a composite material, and the like. In addition, heretofore processing of such nanostructured materials has failed to provide processing parameters that optimize the properties thereof. Therefore, a process that optimizes the thermoelectric properties of a thermoelectric material would be desirable.